Elimination of artifacts in captured images of LED tile displays

ABSTRACT

Systems and methods for moving image capture from video displays that use pulse width modulation (PWM) control are disclosed. In particular, systems and methods for synchronizing display and camera timing so as to reduce or eliminate artifacts appearing in the captured moving images due to unsynchronized interaction between camera shutter/exposure timing and the timing of the display PWM control signal.

RELATED APPLICATION DATA

This application claims the benefit of priority of U.S. ProvisionalPatent Application Ser. No. 62/706,500, filed Aug. 20, 2020, and titled“Elimination of Artifacts in Captured Images of LED Tile Displays”,which is incorporated by reference herein in its entirety.

FIELD OF THE DISCLOSURE

The present disclosure generally relates to the fields of LED displaysand motion picture capture. In particular, the present disclosure isdirected to systems and methods for motion picture capture of pulsewidth modulation (PWM) driven displays while minimizing or eliminatingartifacts resulting from shutter timing in the capture device.

BACKGROUND

Motion picture capture is frequently done using cameras employing a“rolling shutter” in which the shutter scans across the scene capturedin a single frame. This type of image capture can be simulatedelectronically in digital cameras. Global shutters also may experience arolling shutter-like effect depending on the shutter speed setting. Inmotion picture capture, a common shutter speed is 180 degrees, meaningthat 180 degrees out of a 360 degree rotation cycle exposes the camerasensor.

When capturing moving images with this type of camera device, LEDdisplay tiles can be difficult to capture properly without artifactsbecause LED displays employ pulse width modulation (PWM) control withLEDs pulsing at very different rates relative to the camera's exposurecycle. The LED pulses are extremely rapid and can often only partiallyrefresh while a scanning type shutter is in a fully open position. Thesame challenges are presented by other types of PWM driven displays.

Typically, LEDs are grouped in multiplexing scan groups with as few asfour (4) LEDs in a group or as many as thirty-two (32) or more. Thismeans that as a result of the PWM control, only one-fourth (¼) toone-thirty-second ( 1/32) of the LEDs are on at any given moment intime. The misalignment of the camera shutter and scan groups of LEDsthus can create pulsing or banding artifacts on the camera's output asshown in FIG. 11 below. (Note that in the image captured in FIG. 11, thecamera was set at a shutter angle of about 11 deg. in order to make theartifacts more apparent only for the purpose of clarity of illustrationhere).

With the increasing use of LED display walls as backgrounds fortelevision and movie production, there is a need for new solutions thatprovide improved image capture and reduce computing resources necessaryto achieve high-quality captured images.

SUMMARY

In one implementation, the present disclosure is directed to a method ofimage capture of a scene including at least one display driven by a PWMcontrol signal. The method includes initiating image capture with animage capture device at an initial time with the PWM control signal setto off at the initial time; setting the PWM control signal to on after afirst partial shutter period of the image capture device; maintainingthe PWM control signal at on during an open shutter period of the imagecapture device; setting the PWM control signal to off at or before asecond partial shutter period of the image capture device; and repeatingeach the setting and maintaining of the PWM control signal through aseries of image capture frames.

In another implementation, the present disclosure is directed to amethod of image capture of a scene including at least one display drivenby a PWM control signal using at least one image capture device whereinthe image capture device captures images in frames with each frameincluding at least one partial shutter period, an open shutter periodand a closed shutter period. The method includes dividing each frameinto a plurality of time slices; setting the PWM control signal to offduring time slices aligned in whole or in part with the partial shutterperiods; setting the PWM control signal to on during time slices alignedin whole or in part with the open shutter periods; initiating imagecapture with the PWM control signal settings; and maintaining the PWMcontrol settings through a series of image capture frames.

In still another implementation, the present disclosure is directed to amethod of image capture of a scene including at least one display usingat least one image capture device. The method includes displaying on theat least one display a first static color during a sync delay timebeginning at an initial time; displaying on the at least one display asecond static color during a sync on time beginning after the sync delaytime; displaying on the at least one display a third static color afterthe sync on time; capturing an image of the at least one display devicewith the image capture device; adjusting the sync delay time and thesync on time until the first and third static colors do not appear inthe captured image of the at least one display; changing the secondstatic color of a desired video feed; and capturing the scene includingthe at least one display displaying the desired video feed.

In yet another implementation, the present disclosure is directed to animage capture system. The system includes an image capture deviceconfigured to capture a moving image of a scene, the image capturedevice comprising a shutter mechanism capturing images in a series offrames, each frame including an open shutter period preceded andfollowed by partial shutter periods; a system display device thatincludes: a light emitting display surface configured to display imageswithin the scene captured by the image capture device, and a driverconfigured to drive the light emitting display surface with a PWMcontrol signal; and a control device that: sets the PWM control signalto off during partial shutter periods of the image capture device, andsets the PWM control signal to on during open shutter periods of theimage capture device.

In still yet another implementation, the present disclosure is directedto a method of identifying an open shutter period for an image capturedevice during image capture of a scene including at least one PWM drivendisplay device. The method includes displaying on the at least onedisplay a first static color during an initial sync delay time beginningat an initial time; displaying on the at least one display a secondstatic color during an initial sync on time beginning after the initialsync delay time; displaying on the at least one display a third staticcolor after the initial sync on time; capturing an image of the at leastone display device with the image capture device; adjusting the initialsync delay time and the initial sync on time until the first and thirdstatic colors do not appear in the captured image of the at least onedisplay; and identifying a time period when the second static colorappears in the display after the adjusting as the open shutter periodfor the image capture device.

BRIEF DESCRIPTION OF THE DRAWINGS

For the purpose of illustrating the disclosure, the drawings showaspects of one or more embodiments of the disclosure. However, it shouldbe understood that the present disclosure is not limited to the precisearrangements and instrumentalities shown in the drawings, wherein:

FIG. 1 schematically depicts a system according to embodiments disclosedherein.

FIG. 1A schematically depicts an alternative system according toembodiments disclosed herein.

FIG. 2 is a timing diagram illustrating shutter timing relative totiming of PWM control of an LED tile display according to an embodimentof the present disclosure.

FIGS. 3A, 3B and 3C are timing diagrams illustrating examples of PWMtiming and synchronization control methods according to embodiments ofthe present disclosure.

FIG. 4 is a timing diagram illustrating timing of an electronic rollingshutter relative to timing of PWM control of an LED tile displayaccording to another embodiment of the present disclosure.

FIG. 5 illustrates an embodiment of a graphical user interface accordingto the present disclosure.

FIG. 6 shows another embodiment of a user interface configured to allowdirect time control of a Sync Delay parameter.

FIG. 7 is a schematic side-view of an LED tile.

FIG. 8 is a timing diagram illustrating synchronization of multiplecameras with a PWM control signal as in another embodiment of thepresent disclosure.

FIG. 9 is a schematic depiction of another alternative embodiment with athree-dimensional light-emitting display volume and two image capturedevices according to the present disclosure.

FIG. 10 is a block diagram showing an example of a system, camera ordisplay controller according to the present disclosure.

FIG. 11 is an image capture of an LED tile video display presentingartifacts due to use of an uncompensated-for rolling shutter.

DETAILED DESCRIPTION

The present disclosure describes systems and methods for moving imagecapture from video displays that use pulse width modulation (PWM)control. In the disclosed systems and methods, artifacts appearing inthe captured images due to unsynchronized interaction between camerashutter/exposure timing and the timing of the display PWM control signalare reduced or eliminated by precisely controlling display on and offtimes. Systems and methods disclosed herein divide or logically “slice”each frame of video into multiple sub-frame partitions (“time zones”),and then each partition can be individually controlled relative to theimage capture device shutter/exposure timing to allow precise timingcontrol of the PWM signal relative to the shutter timing of the imagecapture device.

While LED displays are referenced herein in the exemplary embodimentsfor illustration purposes, as will be appreciated by persons skilled inthe art, the principles of the present disclosure are equally applicableto any type of display employing PWM control. Examples of other displaytypes include, but are not limited to, organic light-emitting diodes(OLED), polymer light-emitting diodes (PLED), active-matrixlight-emitting diodes (AMOLED), liquid crystal displays (LCD) orlight-emitting electrochemical cells (LEC). The scope of the presentdisclosure and appended claims is therefore not limited to theillustrative LED display examples.

FIG. 1 illustrates basic components in an example of a system accordingto the present disclosure. As shown therein, system 100 includes animage capture device 110, such as a video camera with a digital imagesensor. Image capture device 110 is used to capture a moving scene,which includes within the camera field of view (B) LED display 112 andmay optionally include a presenter (126) or other live action sceneoccurring in front of the display. LED display 112 may comprise largevideo display walls formed by assembling panels containing arrays of LEDpixels. The basics of constructing and controlling such large LED videodisplay walls are generally understood in the art. Internationalapplication No. PCT/US2020/057385, filed Oct. 26, 2020, by the presentApplicant, entitled “Unlimited Pixel Canvas For LED Video Walls”describes embodiments of next-generation large LED video display wallswith improved structures and control, and is incorporated by referencein its entirety herein. Image capture device 110 and display 112 arecontrolled by camera controller 114 and display controller 116,respectively. Each controller comprises one or more processors, memory,software, communications, API and other components as described in moredetail hereinbelow. Bi-directional communication links 120 and 122between the controllers and the controlled devices may be wireless orwired. Optionally, communication link 124 may be provided betweencontrollers 114 and 116.

FIG. 1A illustrates an alternative system embodiment 100A, in whichimage capture device 110 and display 112 are controlled by commoncontroller 118. Controller 118 may be configured generally in the samemanner as controllers 114 and 116 and as further described herein below.Again, wireless or wired communication links 120 and 122 providebi-directional communication between the controller and controlleddevices.

Table 1 below provides a basic illustration of the shutter timing for animage capture device such as video camera 110. This basic illustrationdescribes shutter timing for both mechanical, “rolling shutter” typecapture devices, such as traditional motion picture cameras, and forvarious types of digital capture devices employing digital imagesensors. As shown in Table 1, there are three distinct camera shutterstates during the time of a single frame, wherein the “C” staterepresents a time window when the shutter is fully closed (closedshutter period), the “O” state represents a time window when the shutteris fully open (open shutter period), and the “P” state represents a timewindow when the shutter is opening or closing such that the amount oflight permitted to reach the sensor during these time fields will varywith the shutter movement (partial shutter period).

TABLE 1 camera shutter zones CCCCC PPP OOOOOOOOOOOOOOOOOOOOO PPP CCCCCThe duration and timing of each of these time windows is specific toparticular image capture devices and can vary from device to device. Theteachings of the present disclosure thus apply to any image capturedevice employing a shutter mechanism, whether mechanical or digitallysimulated, that presents a form of the shutter states shown in Table 1.

During P time fields, also referred to herein as “partial shutter,” notall photons emitted by the source reach the image sensor, whether filmor a digital sensor. In order to reduce or eliminate artifacts createdby the pulses of a PWM controlled LED display, as shown in FIG. 11, theLED tile should not output any light during the P time fields. Duringthe O time fields the LED tile should complete all PWM refresh cycles,and during the C time fields no output from the LED tiles is needed.However, if the LED tile is also being observed live by human viewers(in addition to the image capture device), a comfort level light outputmay be emitted during the C time fields so as to avoid a flicker effectvisible to the human eye. It is to be further noted that the timeintervals for the P and O time fields may change value based on fixedcamera parameters such as characteristics of the digital sensor andselectable camera parameters such as shutter angle settings used togenerate the image of the LED display.

FIG. 2 illustrates timing control of the LED PWM control signal relativeto a digital camera sensor charge state across two camera shutterperiods for some embodiments disclosed herein. Top row boxes 10 indicatethe digital sensor charge states (1-8), beginning at a relative timereference (T₀), i.e., the beginning of a single camera shutter period.The camera shutter period begins at T₀ and ends at T₅, which is also T₀for the next shutter period. A single shutter period corresponds to asingle video capture frame. Wider black line 20 indicates simulatedshutter open vs. closed states, wherein the solid black line portion 22represents fully closed (C in Table 1), the dashed line portion 24represents partially open (P in Table 1), and the gap portion 26represents the fully open state (O in Table 1). Line 30 represents thePWM control signal to the LED display and the various arrows (A throughC) represent different time control windows across the shutter period.

The shutter period, with reference to the state-of-charge of the digitalsensor, occurs as follows:

-   -   (1) At the beginning of each exposure the sensor resets all        photosites to empty them of any charge. Conventionally, and from        the perspective of the camera not taking into account the        teachings of the present disclosure, this has been thought of as        the start of the exposure time.    -   (2) Photosites are reset one after the other, for example,        starting with the top left photosite, creating a partial charge        state. The reset process scans down line by line to the bottom        right. During this partial charge state, only a portion of the        light created by an image source is received by the camera        sensor. (Some sensors scan in different directions but the        effect is the same).    -   (3) Fully open exposure time begins at full photosite reset.        This is the beginning of time window B.    -   (4) During the fully open exposure time, the photosites        accumulate charge based on how much light is received from the        image source. The more light falls on each photosite, the higher        the charge. Subject to other camera settings, such as aperture        size, all light emitted by the source is received by the sensor        during this time.    -   (5) Once the fully open exposure time is over, the charge in        each photosite is measured and read out. This is the end of time        window B.    -   (6) The read-out also occurs starting from top left. Again, this        is a partial charge state, during which time only a portion of        the light created by an image source is received by the camera        sensor.    -   (7) The read-out scans down line-by-line to the bottom right        until all photosites are read, ending the partial charge state.    -   (8) At the end of the shutter period, after the read-out of the        photosites, there generally will be a time period during which        the photosites convert light into a charge. Typically during        this time period any captured charge is ignored until the next        reset. The length of this time period will depend on the        specific camera/sensor design, setup and control.

During time window B, when the shutter is fully open with the digitalsensor receiving full charge (sensor states (3)-(5), corresponding tothe O time field in Table 1), LED PWM control signal 30 is delivered atits full on state 32, which is a pulse control configured to present thedesired tile brightness as is understood for PWM control of LED tiledisplays in general. It is the partial shutter periods, e.g., sensorstates (1)-(2) corresponding to time window A2, and sensor states(6)-(7) corresponding to time window C1, during which the LED PWMcontrol signal 30 must be set to off 34 in order to minimize oreliminate artifacts in the moving image captured from the LED display.During times when the shutter is fully closed, e.g., digital sensorstate (8) corresponding to time windows C2 and A1, from the perspectiveof image capture alone, no PWM signal is necessary. However, if visualappearance to a live, in-person viewer of the display is a concern, thenan optional PWM signal 36 may be delivered to the display, which maycorrespond to the overall video stream or may present a momentary staticcolor or other still image to smooth or eliminate any visuallyperceptible flashing of the display.

In general with respect to FIG. 2, time T0 represents the beginning of ashutter period for a single frame. Time T1 represents the beginning ofthe fully open shutter window during which the LED tiles are to be atfull display values, and time T2 represents the end of the fully openshutter window. Time T3 represents the end of the shutter closing stateand beginning of the closed shutter duration. Time T4 represents themidpoint of the camera sensor off time within a shutter period. Time T5represents the end of a shutter period and corresponds to time T0 forthe next subsequent shutter period. The length of time window B (the Otime field in Table 1) when PWM control is set on thus corresponds toT2-T1. As explained further below, the minimum PWM off time forelimination of artifacts corresponds to time windows A2 (T0-T1) and C1(T2-T3).

While the LED display should be on as much as possible while the digitalsensor is fully exposed, i.e., time window B, which provides a goodimage on camera without artifacts, a strobing effect in person can becreated as mentioned if the display or large sections of the display arenot also on during the remainder of the shutter period. However,balancing of artifact elimination with suppression of strobing effectscreates added complexity because LEDs of the display still must becycled off at least during the partial shutter state of time windows A2and C1. Thus, optimally there are very short and precise time windowsduring which the PWM control signal should be off to present good on andoff-camera appearance.

To further illustrate the principles of the present disclosure, FIGS.3A, 3B and 3C present examples of synchronization of camera settingswith PWM signal timing based on a camera set to a 180 degree shutterangle at 60 frames per second (fps). With these settings, as is known inthe art, the camera frame time is 16.6 milliseconds (ms) and the nominalexposure time is 8.3 ms. As explained above, the nominal exposure timeincludes the camera sensor charge and discharge times. Thus, if thecamera sensor has a total charge/discharge time of 5.0 ms, then the timewindow available for clear video capture is 3.3 ms (i.e. time window B),starting after the initial 2.5 ms sensor charge time. However, if thecamera manufacturer does not publish the timing specifications for thesensor, the operator may not know how the total exposure time of 8.3 msis allotted between charge/discharge and fully open, and therefore notknow when to set the PWM signal to on and off as described above.

To solve this problem, in certain embodiments, the operator may usevisual feedback from the captured image to determine the correct timingsettings as illustrated in FIGS. 3A and 3B. As illustrated therein,timing synchronization begins at T0, when the camera is turned on orotherwise begins capture of the initial frame. Before T0, the displayPWM signal 30, here represented as a 1000 Hz PWM signal at 50% dutycycle, initially may be on or off at 38 prior to the first camera frame.Portions of the PWM signal at 34 are off and portions at 32 are on.

Given the chosen frame rate and camera shutter angle, based onfamiliarity with the system equipment and its performance, an operatormay make an initial estimation of a Sync Delay time and a Sync On time.The Sync Delay time is the time prior to the fully open shutter windowB, i.e., the time window A2 between times T0 and T1 in FIG. 2 when thePWM signal should be off to avoid artifacts in the capture image. TheSync On time is the time following the Sync Delay time corresponding tofully open shutter window B, i.e., time between T1 and T2 in FIG. 2,when the PWM signal should be on for optimum image capture. For theexample camera system described in the preceding paragraph, FIG. 3Aillustrates the results of an initial Sync Delay time estimate of 2.0 msand initial Sync On time estimate of 5.0 ms. After initiating imagecapture with these initial Sync time settings, the operator observes thecaptured image to determine the presence of artifacts in the capturedimage resulting from the display being on during one or both the partialshutter states of A2 and C1 (as identified in FIG. 2).

FIG. 3A shows that an observer would see artifacts in the captured imageat both the leading edge and trailing edge of the fully open shutterwindow B. Artifacts at the leading edge of the fully open shutter windowB would be created by the first PWM pulse 32 falling at the end of the2.0 ms Sync Delay time, but before time T1, because the light emitted inthat first pulse would be only partially captured by the image sensor inthe partial charge state. Similarly, artifacts at the trailing edge ofthe fully open shutter window B would be created by the last PWM pulse32 falling after the close of fully open shutter window B, after timeT2, again in the partial charge (discharge) state of the camera sensorbetween times T2 and T3. By identifying these artifacts in the capturedimage, the operator knows that both the Sync Delay time is too short andthat the Sync On time is too long for that specific camera set up.

With the knowledge gained from an initial Sync time estimate, theoperator may make a revised estimate, increasing the Sync Delay time tofurther postpone the PWM on signal 32 (to eliminate leading edgeartifacts) and decreasing the Sync On time to further advance the PWMoff signal 34 at the end of the fully open shutter window B (toeliminate trailing edge artifacts). Thus, as illustrated in FIG. 3B, theSync Delay time may be set at 2.5 ms and the Sync On time set at 3.5 ms.The Sync Delay time of 2.5 ms turns on the PWM such that a first onpulse 32 falls at time T1, the beginning of the fully open shutterwindow B. With this setting the operator will observe no leading edgeartifacts in the captured image and thus know that time T1, thebeginning of the fully open shutter window B, has been correctlyidentified. As also illustrated in FIG. 3B, the Sync On time of 3.5 mscauses the last on pulse 32A of PWM signal 30 to fall across time T2 by,with a time portion X of pulse 32A falling within the following partialshutter period (window C1 in FIG. 2). In this specific example, theoverlapping time portion X of final pulse 32A is 0.2 ms. Depending on avariety of other factors in camera set up and display parameters, the0.2 ms of pulse 32A falling after time T2 may or may not create trailingedge artifacts that are significant enough to unacceptably degrade theappearance of the captured image.

In the event that trailing edge artifacts created by the portion ofpulse 32A falling after time T2 unacceptably degrade the captured image,there are a number of control options available in alternativeembodiments. In general, depending on the PWM frequency and duty cycle,the pulses may not align precisely with the available open shutterwindow B. For example, as in FIG. 3B, with the PWM signal driven at 1000Hz and 50% duty cycle, pulse leading edges fall 1.0 ms apart and eachhave an on time of 0.5 ms. With camera sensor timing parameters fixed asin this example, physical constraints of the system mean that it is notpossible to turn on the PWM signal at T1 and then off exactly at T2, 3.3ms later because this PWM signal can only be controlled in 0.5 mssegments. One solution is to further decrease the Sync On time by asufficient amount to move the last pulse so as to fall entirely withinfully open shutter window B. In this particular example, that meansdecreasing the Sync On time to something less than 3.0 ms, so that onlythree full pulses occur during fully open shutter window B between timesT1 and T2. However, such a solution may, in some cases, degrade otheraspects of the captured image, such as brightness, because it may notmaximize use of available fully open shutter time.

In some instances, another possible solution is to adjust the PWM signalso that the pulses more precisely align with the fully open shutterwindow B. In one option this can be done by altering the duty cycle ofthe PWM signal while maintaining the frequency. Decreasing the dutyincreases or decreases the amount of on time for each pulse withoutchanging the leading edge separation. Thus, with the same Sync Delaytime and Sync On time shown in FIG. 3B, a 1000 Hz PWM signal at 30% dutycycle rather than 50%, would put four full on pulses within the fullyopen shutter window B, with no portion of the final pulse falling aftertime T2. However, decreasing the duty cycle may not be an option in somesituations as it also has an effect on the displayed images. Anotheroption, if permitted by hardware constraints, such as capabilities ofLED tile controllers, is to adjust the PWM frequency to align the pulseswith the time window. One example of such an adjustment is shown in FIG.3C. In this case, increasing the PWM frequency from 1000 Hz to 2000 Hz(maintaining the 50% duty cycle) allows the same Sync Delay time of 2.5ms with a Sync On time of 3.3 ms without placing a pulse after time T2because the trailing edge of the final pulse 32 falls at 3.25 ms of the3.3 ms fully open shutter window B. As will be noted by persons skilledin the art, the 1000 Hz and 2000 Hz PWM signals used in these examplesare convenient for illustrating principles of the present disclosure ina simplified manner. In practice, high resolution video walls mayoperate at frequencies of 8000 Hz or higher. The principles of thepresent disclosure apply equally to systems operating at such higherfrequencies.

In further alternative embodiments, a convenient way of implementing thecontrol methodology of the present disclosure in processor-controlledsystems is to create a plurality of regular time control slices withineach camera frame. Because each camera model and manufacturer will varyshutter and/or charge state timing, it can be desirable to create thesetime control slices as virtual “time zones” within each shutter periodin order to individually select which time slices should display video(PWM on) and which should not (PWM off). Theoretically, the larger thenumber of time slices, the finer the control possible. However, thenumber of time slices may be limited based on the capability of the LEDtile (combination of processing power, driver integrated circuit, etc.).

An illustration of the use of such virtual time control slices ispresented in FIG. 4, wherein nine equal time control slices areoverlayed on a single shutter period timing diagram. The individual timecontrol slices are designated as (1)-(9). As shown therein, referencelines 40 indicate the beginning/end of each time control slice. In thisexample, in order to avoid unwanted artifacts in the captured video, PWMsignal 30 is set to off 34 during at least time control slices (1), (5)and (6). This solution fits well with LED PWM methodology and typicalcamera systems, as well as being tunable across a variety of products.Additionally, during time control slices (7)-(9), aligned with the fullyclosed camera shutter time, the PWM signal is optionally on 36 todisplay video or a static image/color to smooth strobing effects, whilehaving no impact on the captured image.

With higher performance LED display tiles more (smaller) time controlslices can be created, allowing for more precise control of the on/offswitching of the PWM control signal. For example, persons skilled in theart may recognize that the end of the fully open shutter window B inFIG. 4 (T2) falls at approximately the mid-point of time control slice(5). Using the nine time control slices as shown, a decision must bemade as to whether to set the PWM control signal on during time controlslice (5), which may create artifacts during the partial sensor chargestate, or set PWM control signal off, which then does not fully utilizeopen shutter window B and may compromise characteristics of the capturedimage. To avoid the necessity of such a tradeoff, it may be desirable insome situations to double the number of time control slices so as tomore precisely align the PWM control with the shutter timing. In thisexample, if eighteen time control slices were used instead of nine asshown, the end of the seventh zone would align with time T2 and thusallow for at least one additional on pulse of the PWM control signalwithin fully open shutter window B.

In a further alternative embodiment, a Sync Phase parameter may beincorporated to allow adjustment of the phase of the camera-to-LEDtiming. It may be preferred for both the camera and PWM timing to be“locked” together, where the rate of camera exposure is the same as therate of the PWM on/off cycles. However, while these systems may updateat the same rate, often they will not be in phase, yet they will have aconsistent phase offset. Thus, in order to ensure that the time zones asdescribed above are aligned as best as possible with the camera sensorfully open/partial-opening/closing periods, a Sync Phase parameter cannudge the phase of the LED on/off cycles. An embodiment of such a SyncPhase parameter is graphically illustrated in FIG. 4, wherein line 40represents the beginning of an individual time control slice asdescribed above and the Sync Phase parameter is represented by delaytime 42 or advance time (negative delay) 44. The Sync Phase parametermay be a software-implemented feature in the video processor/controlsystem that allows shifting of the time zones as shown, either addingnanoseconds and shifting to the right or subtracting nanoseconds andshifting to the left.

Based on the teachings of the present disclosure, users of the disclosedsystems and methods, such as filmmakers, artists or camera operators,may select their preferred camera shutter angles based on desiredartistic effect, lighting conditions, lensing, set design, etc. In onecontrol aspect, display/video signal PWM cycles can be reduced andpulses somewhat widened to reduce the number of timing zones, forexample increasing the period of the zones. In another control aspect,desired shutter angle versus available slice refresh times can beadjusted. By shifting the timing of the video signal and the camerashutter angle, desired display timing slices are captured along with anylive action in the foreground. Embodiments disclosed herein thus providefar more control options than prior art systems by facilitatingcomplimentary control of both the display PWM signal and cameratiming/shutter angle. Thus, while the display/video signal controloptions may be limited by the number of PWM cycles that can be shown perframe period, when combined with shutter timing/angle control, virtuallyunlimited artistic effects can be created based on user preference.

In further aspects of the present disclosure, user interfaces areprovided to aid with finding correct synchronization timing. In oneembodiment, as shown in FIG. 5, user interface 130 can be used tofacilitate user control of the Sync Delay time and Sync On timeparameters based on visual feedback of the images produced during aset-up routine. Also, using interface 130, a control system isconfigurable to show solid colors during specific timing slices. Displayof easily identifiable solid colors on the display allows visualverification of timing alignment as described above in connection withFIGS. 3A and 3B. For example, if red is displayed for the first timingslice, followed by green for the middle timing slices, and then atrailing red in the final timing slice, the synchronization timing canbe more easily adjusted using these reference colors so that the cameraonly captures a red+green for the displayed reference image.

User interface 130 allows a user to precisely select a desired PWMcontrol signal start, end and on time for the LED tile using a displaycontroller such as controllers 116 or 118. User interface 130 includes agraphical representation of shutter timing 132 for a specific imagecapture device to be used. Shutter timing for specific cameras can beobtained from manufacturer's specifications or may be set in the camera,for example via the camera controller. In some embodiments, the imagecapture device may directly communicate with the LED display controlsystem to automatedly input shutter timing information as shown, forexample, in FIG. 1A. Slider bar 134, which may be a virtual,touch-screen slider, allows the user to set the LED PWM control on timeto correspond to the shutter opening times and to fine tune therelationship to achieve desired appearance of the image produced withthe camera. Each end of the slider bar may be moved independently toalter the sync delay at the beginning of the shutter frame and the deadtime at the end. Visual feedback from the display allows determinationof the slider position, i.e. Sync Delay value, that provides a desiredappearance in the captured video stream.

Test color selection section 136 of user interface 130 allows more finetuning of the LED sync delay with the shutter opening times using thecolor selection boxes for colors 1, 2 and 3. In this illustrativeexample, three color selection boxes are provided, corresponding to theSync Delay time, the Sync On time and the closed/dead time at the end ofthe frame period. Additional color selection boxes may be provided basedon user preference. Alternatively, rather than static single colors, anystatic image may be displayed. Providing selectable color options syncedto specific shutter periods can be highly useful in finding theclosed/opening/open/closing/closed portions of the camera shutter,especially when the camera manufacturer does not publish the details ofhow and when the shutter is open. For example, a user could set Color 1to “Red” and move the Sync Delay slider 134 forward and backward untilthe Red color is just barely visible in the “Open” region of the shutterperiod (i.e. time period B in FIG. 2). Doing so allows preciseidentification and setting of the beginning of the LED PWM “on” time,after which the Color 1 can be reset to Black. Next, Color 3 can be setto another color, such as “Green”, and the Dead Time (PWM “off” cycle)can be adjusted forward and back until the captured image is just barelyvisible in Green and thereafter Color 3 can be reset to Black. Toconfirm these settings made by the slider, Color 2 can be chosen toconfirm that the Sync On time aligns the image capture device to berecording and outputting the chosen color without artifacts. Once thesettings to eliminate artifacts are validated, “Color 2” would be resetto “Video”, whereafter the display and image capture device can be usednormally with LED display synchronized to the shutter period of theimage capture device so as to avoid artifacts in the captured imagestream.

In situations where the specific camera timing is not known, slider bar134 of user interface 130 (FIG. 5), with color selection boxes 136 canbe used to visually identify the available open shutter window and setPWM timing as described. Alternatively, where the specific camera timingis known (e.g. shutter opening/closing time and charge/discharge time),the available shutter open window can be precomputed and the appropriatePWM cycle length and off time set with an alternative user interface asshown in FIG. 6.

In some embodiments, user interface 130 may be configured as agraphical-user interface (GUI) presented on a user interface displaydevice based on interface instructions executed by a system processor.Such a GUI may be presented with multiple GUI regions, for example, afirst GUI region 130 a, containing the control elements as discussedabove, and a second GUI region 130 b, containing a display window 138presenting the captured image. FIG. 11 presents an example of a capturedimage in a GUI display window such as window 138.

In another alternative embodiment, aspects of the synchronizationcontrol may be embedded in individual tiles in order to reduce bandwidthrequirements for tile-to-tile and tile-to-system control communications.FIG. 7 illustrates a typical LED display tile 150 as may be used in thecreation of video walls. High level components include the LED pixelarray 152 and component housing 154, which includes components such astile controller 156 and multiple connectors 158. Tile controller 156includes processing and storage for executing functions such as videopacket switching, directing the video signal to appropriate pixels andcommunications between tiles and through tiles to the system control.Individual tile controllers 156 also control the PWM signal in many tiledesigns. Tile connectors 158 are typically disposed on each tile edge tofacilitate communication with adjacent tiles for relay of tileidentification information, control signals and video signals.Connectors may be physical connections or communicate via a variety ofwireless protocols as will be understood by persons skilled in the art.

In a typical application a video source is fed into the processor, theprocessor divides the feed into tile-sized pieces (or in IP-basedsystems, packetizes the video feed), sends those pieces or packets tothe tiles. The tiles in turn emit that data as light as a PWM signalreproducing the video source on the display wall at a brightness set bythe PWM signal. The processing and sending of the video data from thecontroller/processor to the tiles uses CPU capacity and communicationchannel bandwidth. Adding multiple additional time zone control to thevideo signal and embedding additional static color signals withinspecific time slices uses additional CPU capacity and communicationchannel bandwidth. In some systems, very high resolution video wallsystems may already be operating at close to CPU capacity and/orcommunication channel bandwidth, and thus unable to take advantage ofsynchronization and strobe smoothing techniques disclosed herein if thetime zones and/or static color control signals are embedded with thevideo signal. In order to reduce demand on the CPU or communicationschannel, instead of embedding these control signals with the videosignal, time zones with on/off instructions and/or timing for staticcolor displays (such as during time periods A1 and C2 in FIG. 2 asdescribed above) are sent to the tiles ahead of time with instructionsstored in a tile memory to cause the tile controller to turn PWM on andoff and/or display the required color at the specified time. Bysequencing the control signals in this manner and utilizing the existingtile memory and processing capabilities, CPU capacity and/orcommunication channel bandwidth can be freed up to allow for, interalia, more video to more tiles or higher resolution video, thusimproving operation of the controller, communications and overall systemperformance.

As a practical example of the foregoing, in order to provide foursub-frames for a 60 fps system, the video can be delivered at 240 fps.However, this high frame rate reduces the overall system processingcapacity by 4×, requiring much more sophisticated equipment upstream tosend faster data, and therefore may not allow for precise fine tuning ofthe shutter timing synchronization as described herein. Generating thesub-frame timing zones and static fill colors in the endpoint, i.e. inthe tile controllers, based on pre-delivered instructions, may makeshutter synchronization control possible in that system where itotherwise might not be. Adding a chromakey color, for example, or aninverse of a video field, can be done calculated in advance and does notrequire a video payload to deliver such information.

FIG. 8 illustrates a further alternative embodiment in which multiplecameras are employed, capturing at different phase offsets, thus exposedat different portions of the video frame period and capturing differentvideo time control slices to allow for a greater variety of videoeffects. In the illustrated example, the video frame period iscontrolled with eight (8) time control slices and two cameras are used.Camera1 and Camera2 are configured with the same shutter frequency, butat a phase offset. Using the control sequence as shown in FIG. 8, theLED PWM signal (30) “on” time can be aligned with each cameraindependently if enough sub-frame time control slices are used. As showntherein, time control slices (1) and (2) are active video slicescorresponding to Camera1 open shutter window (B_(V1)) and time controlslices (6) and (7) are active video slices corresponding to Camera2 openshutter window (B_(V2)). According to the principles described hereinabove, time control slices (3), (5) and (8), which align with camerasensor partial charge states, are set to display black to avoid creationof artifacts in the captured video streams, and time control slice (4),which falls in a shutter closed time for both cameras, displays a staticcolor as desired to reduce strobing effects for live viewers. The timingfor two cameras illustrated in FIG. 8 is merely illustrative of amulti-camera embodiment. Any number of cameras may be used based on theteachings presented herein, generally limited only by the capabilitiesof the equipment. Multi-camera embodiments provide an improvement overexisting systems by allowing display of different background videocontent within specific time frames to permit the different cameras tocapture different backgrounds while still focused on the same foregroundaction.

FIG. 9 illustrates a further alternative system 160 employing alight-emitting three-dimensional volume as display 112, with two imagecapture devices 110 a and 110 b, the timing for which is described abovein connection with FIG. 8. In this embodiment, the light-emittingthree-dimensional volume is comprised of arrays of light-emitting tiles150 as shown in FIG. 7. Controller 116 and communication links 120, 122,and 124 may be configured by persons skilled in the art based on theteachings of the present disclosure and as elsewhere described herein.System 160 allows a live action scene to be captured within thethree-dimensional volume, surrounded video supplied virtual environment,all of which is simultaneously captured by image capture devices 110 aand 110 b.

As may be appreciated by persons skilled in the art, certain controlconfigurations according to the present disclosure may result inrelatively shorter capture periods meaning that less light is receivedby the camera sensor than otherwise may be the case. A number of optionsmay be employed for adjusting brightness of the captured image in thissituation, such as increasing the PWM on time (higher duty cycle) makingthe display brighter, adjusting the camera's aperture to let in more ofthe light, removing any ND (Neutral Density) filters that the camera mayhave been using, adjusting the shutter angle (within PWM limits), andincreasing the camera's sensor sensitivity (ISO). In specific situationswith specific equipment, other options for brightness control may bepresented to achieve any desired image capture quality or artisticeffects.

In some embodiments, control functions, such as camera control 114,display control 118 or tile control 156, may be executed as one or morecomputing devices 200 as illustrated in FIG. 10. In this example,computing device 200 includes one or more processors 202, memory 204,storage device 206, high speed interface 208 connecting to memory 204and high speed expansion ports 210, and a low speed interface 212connecting to low speed bus 214 and storage device 206. Each of thecomponents 202, 204, 206, 208, 210, and 212, are interconnected usingvarious busses or other suitable connections as indicated in FIG. 10 byarrows connecting components. The processor 202 can process instructionsfor execution within the computing device 200, including instructionsstored in the memory 204 or on the storage device 206 to displaygraphical information via GUI 218 with display 220, or on an externaluser interface device, coupled to high speed interface 208. In otherimplementations, multiple processors and/or multiple buses may be used,as appropriate, along with multiple memories and types of memory. Also,multiple computing devices 200 may be connected, with each deviceproviding portions of the necessary operations (e.g., as a server bank,a group of blade servers, or a multi-processor system).

Memory 204 stores information within the computing device 200. In oneimplementation, the memory 204 is a computer-readable medium. In oneimplementation, the memory 204 is a volatile memory unit or units. Inanother implementation, the memory 204 is a non-volatile memory unit orunits.

Storage device 206 is capable of providing mass storage for computingdevice 200, and may contain information such as timing control, timeslice size and/or static color chroma and timing as describedhereinabove. In one implementation, storage device 206 is acomputer-readable medium. In various different implementations, storagedevice 206 may be a floppy disk device, a hard disk device, an opticaldisk device, or a tape device, a flash memory or other similar solidstate memory device, or an array of devices, including devices in astorage area network or other configurations. In one implementation, acomputer program product is tangibly embodied in an information carrier.The computer program product contains instructions that, when executed,perform one or more methods, such as those described above. Theinformation carrier is a computer- or machine-readable medium, such asthe memory 204, the storage device 206, or memory on processor 202.

High speed interface 208 manages bandwidth-intensive operations forcomputing device 200, while low speed controller 212 manages lowerbandwidth-intensive operations. Such allocation of duties is exemplaryonly. In one implementation, high speed interface 208 is coupled tomemory 204, display 220 (e.g., through a graphics processor oraccelerator), and to high-speed expansion ports 210, which may acceptvarious expansion cards (not shown). In the implementation, low speedcontroller 212 is coupled to storage device 206 and low speed expansionport 214. The low speed expansion port, which may include variouscommunication ports (e.g., USB, Bluetooth, Ethernet, wireless Ethernet)may be coupled to one or more input/output devices as part of GUI 218 oras a further external user interface, such as a keyboard, a pointingdevice, a scanner, or a networking device such as a switch or router,e.g., through a network adapter.

Various implementations of the systems and techniques described here canbe realized in digital electronic circuitry, integrated circuitry,specially designed ASICs (application specific integrated circuits),computer hardware, firmware, software, and/or combinations thereof.These various implementations can include implementation in one or morecomputer programs that are executable and/or interpretable on aprogrammable system including at least one programmable processor, whichmay be special or general purpose, coupled to receive data andinstructions from, and to transmit data and instructions to, a storagesystem, at least one input device, and at least one output device.

These computer programs (also known as programs, software, softwareapplications or code) include machine instructions for a programmableprocessor, and can be implemented in a high-level procedural and/orobject-oriented programming language, and/or in assembly/machinelanguage. As used herein, the terms “machine-readable medium”“computer-readable medium” refers to any computer program product,apparatus and/or device (e.g., magnetic discs, optical disks, memory,Programmable Logic Devices (PLDs)) used to provide machine instructionsand/or data to a programmable processor, including a machine-readablemedium that receives machine instructions as a machine-readable signal.The term “machine-readable signal” refers to any signal used to providemachine instructions and/or data to a programmable processor.

To provide for interaction with a user, the systems and techniquesdescribed here can be implemented on a computer having a display device(e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor)for displaying information to the user and a keyboard and a pointingdevice (e.g., a mouse or a trackball) by which the user can provideinput to the computer. Other kinds of devices can be used to provide forinteraction with a user as well; for example, feedback provided to theuser can be any form of sensory feedback (e.g., visual feedback,auditory feedback, or tactile feedback); and input from the user can bereceived in any form, including acoustic, speech, or tactile input.

The systems and techniques described here can be implemented in acomputing system that includes a back end component (e.g., as a dataserver), or that includes a middleware component (e.g., an applicationserver), or that includes a front end component (e.g., a client computerhaving a graphical user interface or a Web browser through which a usercan interact with an implementation of the systems and techniquesdescribed here), or any combination of such back end, middleware, orfront end components. The components of the system can be interconnectedby any form or medium of wired or wireless digital data communication(e.g., a communication network). Examples of communication networksinclude a local area network (“LAN”), a wide area network (“WAN”), andthe Internet.

The computing system can include clients and servers. A client andserver are generally remote from each other and typically interactthrough a communication network. The relationship of client and serverarises by virtue of computer programs running on the respectivecomputers and having a client-server relationship to each other.

The foregoing has been a detailed description of illustrativeembodiments of the disclosure. It is noted that in the presentspecification and claims appended hereto, conjunctive language such asis used in the phrases “at least one of X, Y and Z” and “one or more ofX, Y, and Z,” unless specifically stated or indicated otherwise, shallbe taken to mean that each item in the conjunctive list can be presentin any number exclusive of every other item in the list or in any numberin combination with any or all other item(s) in the conjunctive list,each of which may also be present in any number. Applying this generalrule, the conjunctive phrases in the foregoing examples in which theconjunctive list consists of X, Y, and Z shall each encompass: one ormore of X; one or more of Y; one or more of Z; one or more of X and oneor more of Y; one or more of Y and one or more of Z; one or more of Xand one or more of Z; and one or more of X, one or more of Y and one ormore of Z.

Various modifications and additions can be made without departing fromthe spirit and scope of this disclosure. Features of each of the variousembodiments described above may be combined with features of otherdescribed embodiments as appropriate in order to provide a multiplicityof feature combinations in associated new embodiments. Furthermore,while the foregoing describes a number of separate embodiments, what hasbeen described herein is merely illustrative of the application of theprinciples of the present disclosure. Additionally, although particularmethods herein may be illustrated and/or described as being performed ina specific order, the ordering is highly variable within ordinary skillto achieve aspects of the present disclosure. Accordingly, thisdescription is meant to be taken only by way of example, and not tootherwise limit the scope of this disclosure.

Exemplary embodiments have been disclosed above and illustrated in theaccompanying drawings. It will be understood by those skilled in the artthat various changes, omissions and additions may be made to that whichis specifically disclosed herein without departing from the spirit andscope of the present disclosure.

What is claimed is:
 1. A method of image capture of a scene including at least one display driven by a PWM control signal, comprising: initiating image capture with an image capture device at an initial time with the PWM control signal set to off at the initial time; setting the PWM control signal to on after a first partial shutter period of the image capture device; maintaining the PWM control signal at on during an open shutter period of the image capture device; setting the PWM control signal to off at or before a second partial shutter period of the image capture device; and repeating each said setting and maintaining of the PWM control signal through a series of image capture frames.
 2. The method of claim 1, further comprising maintaining the PWM control signal off during a closed shutter period of the image capture device during each of the captured frames.
 3. The method of claim 1, further comprising setting the PWM control signal on during all or part of a closed shutter period of the image capture device during each of the captured frames.
 4. The method of claim 1, wherein said setting the PWM control signal to on after a partial shutter period comprises: setting the PWM control signal to on at an initial sync delay time after the initial time; identifying presence or absence of leading edge artifacts in the captured image; and when leading edge artifacts are present, increasing the sync delay time until leading edge artifacts are reduced or eliminated in the captured image.
 5. The method of claim 4, wherein said setting of the PWM control signal to on after a partial shutter period further comprises, when leading edge artifacts are absent, decreasing the sync delay time until leading edge artifacts appear in the captured image and, subsequently, increasing the sync delay time to a value greater than the sync delay time at which artifacts appeared in the captured image.
 6. The method of claim 4, wherein said setting the PWM control signal to off at or before a second partial shutter period comprises: setting the PWM control signal to off after an initial sync on time following the sync delay time; identifying presence or absence of trailing edge artifacts in the captured image; and when trailing edge artifacts are present, decreasing the sync on time until trailing edge artifacts are reduced or eliminated in the captured image.
 7. The method of claim 6, wherein said setting the PWM control signal to off at or before a second partial shutter period further comprises when trailing edge artifacts are absent, increasing the sync on time until trailing edge artifacts appear in the captured image and, subsequently, decreasing the sync on time to a value less than the sync on time at which artifacts appeared in the captured image.
 8. The method of claim 1, wherein said steps of setting and maintaining comprise: displaying on the at least one display a first static color during an initial sync delay time beginning at the initial time; displaying on the at least one display a second static color during an initial sync on time beginning after the initial sync delay time; displaying on the at least one display a third static color after the initial sync on time; adjusting the initial sync delay time and the initial sync on time until the first and third static colors do not appear in the captured image of the at least one display; selecting as the sync delay time the initial sync delay time at which the first static color does not appear in the captured image; selecting as the sync on time the initial sync on time at which the third static color does not appear in the captured image; setting the PWM control signal to on after the sync delay time; setting the PWM control signal to off after the sync on time; maintaining the PWM control signal at on during the sync on time; and changing the second static color during the sync on time to a desired video feed.
 9. The method of claim 1, further comprising: initiating image capture with a second image capture device at a second initial time, wherein the second initial time begins after the second partial shutter time of the first image capture device; setting the PWM control signal to on after a first partial shutter period of the second image capture device; maintaining the PWM control signal at on during an open shutter period of the second image capture device; setting the PWM control signal to off at or before a second partial shutter period of the second image capture device.
 10. The method of claim 9, further comprising aligning the first partial shutter period of the first image capture device with the second partial shutter period of the second image capture device.
 11. The method of claim 10, wherein the first and second image capture devices have first and second total shutter periods, respectively, and said method further comprises maintaining a constant phase offset between the first and second total shutter periods.
 12. The method of claim 10, wherein the first image capture device is in a closed shutter period during the second image capture device open shutter period.
 13. The method of claim 12, further comprising: aligning a closed shutter period of the first image capture device with a closed shutter period of the second image capture device; and setting the PWM control signal to on during the aligned closed shutter periods.
 14. The method of claim 1, further comprising: dividing each image capture frame into a plurality of time slices; setting the PWM control signal to off during time slices aligned in whole or in part with the partial shutter periods; and setting the PWM control signal to on during time slices aligned in whole or in part with the open shutter periods.
 15. The method of claim 14, wherein the time slices are equal in time length and there is a whole number of time slices in each image capture frame.
 16. A method of image capture of a scene including at least one display driven by a PWM control signal using at least one image capture device wherein the image capture device captures images in frames with each frame including at least one partial shutter period, an open shutter period and a closed shutter period, the method comprising: dividing each frame into a plurality of time slices; setting the PWM control signal to off during time slices aligned in whole or in part with the partial shutter periods; setting the PWM control signal to on during time slices aligned in whole or in part with the open shutter periods; initiating image capture with said PWM control signal settings; and maintaining said PWM control settings through a series of image capture frames.
 17. The method of claim 16, wherein the time slices are equal in time length and there is a whole number of time slices in each image capture frame.
 18. The method of claim 16, further comprising setting the PWM control signal to on during time slices aligned with the closed shutter periods.
 19. The method of claim 16, wherein the PWM control signal is set to on only during time slices aligned in whole with open shutter periods or only during time slices aligned in whole with open and closed shutter periods.
 20. A method of image capture of a scene including at least one display using at least one image capture device, comprising: displaying on the at least one display a first static color during a sync delay time beginning at an initial time; displaying on the at least one display a second static color during a sync on time beginning after the sync delay time; displaying on the at least one display a third static color after the sync on time; capturing an image of the at least one display device with the image capture device; adjusting the sync delay time and the sync on time until the first and third static colors do not appear in the captured image of the at least one display; changing the second static color of a desired video feed; and capturing the scene including the at least one display displaying the desired video feed.
 21. The method of claim 20, wherein the at least one display comprises a display driven by a PWM control signal and wherein the image capture device captures images in frames with each frame including at least one partial shutter period, an open shutter period and a closed shutter period.
 22. An image capture system, comprising: an image capture device configured to capture a moving image of a scene, the image capture device comprising a shutter mechanism capturing images in a series of frames, each frame including an open shutter period preceded and followed by partial shutter periods; a system display device that includes: a light emitting display surface configured to display images within the scene captured by the image capture device, and a driver configured to drive the light emitting display surface with a PWM control signal; and a control device that: sets the PWM control signal to off during partial shutter periods of the image capture device, and sets the PWM control signal to on during open shutter periods of the image capture device.
 23. The system of claim 22, wherein the control device: divides each image capture frame into a plurality of time slices; sets the PWM control signal to off during time slices aligned in whole or in part with the partial shutter periods; and sets the PWM control signal to on during time slices aligned in whole or in part with the open shutter periods.
 24. The system of claim 22, wherein the control device comprises: at least one microprocessor; and a memory in operative communication with the at least one microprocessor, the memory containing machine-executable instructions that, when executed by the at least one microprocessor: set an initial time at initiation of image capture; allow a user to set a sync delay time beginning at the initial time; allow the user to set a sync on time beginning after the sync delay time; turn off the PWM control signal for the sync delay time beginning at the initial time; turn on the PWM control signal for the sync on time after the sync delay time; turn off the PWM control signal after the sync on time; and reset the initial time at the end of each image capture frame.
 25. The system of claim 24, wherein the memory contains further machine-executable instructions that, when executed by the at least one microprocessor: display on a user interface display device a graphical user interface (GUI) with at least a first GUI region permitting user entry of sync delay time values and sync on time values.
 26. The system of claim 25, wherein the memory contains further machine-executable instructions that, when executed by the at least one microprocessor: display the GUI with at least a second GUI region displaying the image captured by the image capture device; present within the first GUI region: a user selectable option to display on the system display device a video feed or a first static color during a sync delay time; a user selectable option to display on the system display device a video feed or a second static color during a sync on time beginning after the sync delay time; and a user selectable option to display on the system display device a video feed or a third static color after the sync on time; whereby adjustment of the sync delay time and the sync on time until the first and third static colors do not appear in the captured image of the at least one display identifies a sync delay time corresponding to an initial partial shutter period and the shutter open period in each image capture frame of the image capture device.
 27. The system of claim 24, wherein the memory contains further machine-executable instructions that, when executed by the at least one microprocessor: divide each image capture frame into a plurality of time slices; and set the PWM control signal to on or off by time slice.
 28. The system of claim 27, wherein: each frame of the image capture device further includes a shutter closed period; the memory further contains machine-executable instructions that, when executed by the at least one microprocessor: allow the user to set the on or off state of the PWM control signal for time slices falling within the closed shutter periods, and allow the user to select a static image or a video feed for display when the PWM state is set to on during the closed shutter periods; and the parti the display device comprises an array of light-emitting tiles, each tile having a tile control configured as the PWM driver for the tile and including at least one tile microprocessor and a tile memory in operative communication with the at least one tile microprocessor, the tile memory containing machine-executable instructions that, when executed by the at least one tile microprocessor display on the tile the static image when selected by the user.
 29. The system of claim 22, wherein: each frame of the image capture device further includes a shutter closed period; and the control device allows a user to set the PWM signal to on or to off during the shutter closed periods.
 30. The system of claim 22, wherein: the system display device comprises a three-dimensional (3D), light-emitting display volume comprising a three-dimensional array of light-emitting tiles joined along tile edges to form a seamless 3D volume display wall, and each said tile includes a unique PWM driver for each said tile; and the image capture device comprises at least one camera with a digital image sensor configured electronically with said shutter mechanism. 